When will i harvest my brussell sprouts they are 5-ft tall with yellow seeds i don't have no sprouts?

If the plants have already gone to seed, you won't get any sprouts from them. We don't know where you live or how warm your weather has been, but Brussel sprouts are a cold weather crop. If you live in the southern U.S., some extension services recommend growing Brussel sprouts only as a fall crop.